UNIVERSITY   OF   CALIFORNIA 

COLLEGE    OF   AGRICULTURE 

AGRICULTURAL   EXPERIMENT  STATION 

CIRCULAR  No.  245 
June,  1922 


VINE  PRUNING  SYSTEMS 

By  FEEDEBIC  T.  BI0LETT1 


The  various  systems  of  vine  pruning  are  distinguished  by  the  form 
that  is  given  to  the  more  or  less  permanent  part  of  the  vine  and  by 
the  kind  and  amount  of  annual  growth  that  is  left  at  the  winter  prun- 
ing. The  systems  which  appear  most  adapted  to  the  conditions  of 
grape  growing  in  California 
belong  to  three  groups :  ( 1 ) 
Head  Pruning;  (2)  Cane 
Pruning;  (.3)  Cordon  Prun- 
ing. 

1.  Head  prumng. — In  sys- 
tems of  this  group  the  vine  is 
given  the  form  of  a  small  self- 
supporting  tree  or  bush.  The 
fully  formed  vine  consists 
of  an  upright  "trunk,"  iy2 
to  3!/2  feet  high,  dividing  at 
the  top  into  a  ring  of  4  to  8 
ascending  "arms,"  6  to  18 
inches  long.  At  the  end  of 
each  of  these  arms  is  left  at 
the  winter  pruning  1  or  2 
"spurs"  consisting  of  1,  2,  or 
3  joints  of  the  basal  portions 
of  the  "canes"  which  grew 
the  preceding  summer. 

Figure  1  shows  a  typical 
head-pruned  vine  of  good 
form  with  a  trunk  18  inches 
high.  This  is  as  low  as  is 
usually  advisable.  Three  well- 
formed  arms  arising  at  a  good 
angle    are     already     about     8      Fig.  1  —  Head  pruned  Muscat  six  years  old. 


UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 


Fig.  2. — Cane  pruned  Sultanina,  eleven  years  old. 


inches  long.  Near  the  base  on  each  of  these  arms  a  spur  has  been  left 
from  which  other  arms  will  develop.  Finally  this  vine  will  have  a 
vase-formed  head  with  about  6  arms.  At  this  stage  it  has  8  spurs 
mostly  with  2  joints,  which  with  the  bud  at  the  base  of  each  spur  gives 
24  possible  fruit  buds. 

However  long  the  vine  lives  the  height  of  the  trunk  will  not  change. 
The  height  of  the  spurs  may  be  controlled  by  a  greater  or  less  elonga- 
tion of  the  arms. 

2.  Cane  pruning. — In  this  system  the  vine  is  given  a  trunk  of 
similar  form  and  from  2  to  3  feet  high.  This  trunk,  on  a  mature  vine, 
divides  at  the  top  into  4  arms,  6  to  12  inches  long.  These  arms  extend 
like  an  open  fan  in  the  direction  of  the  horizontal  wire  which  supports 
the  canes.  At  the  end  of  each  arm  is  left  a  "fruit  cane,"  2  to  5  feet 
long  with  10  to  20  buds  each.  On  weak  vines  1  or  more  of  these  canes 
is  omitted,  on  very  vigorous  vines  one  or  two  extra  canes  may  be  left. 
On  each  arm  is  also  left,  below  the  cane  where  possible,  1  or  occasion- 
ally 2  "renewal  spurs"  of  1  or  2  buds  to  supply  fruit  canes  for  the 
following  year. 

Figure  2  shows  a  cane-pruned  vine  of  good  form  except  that  the 
trunk  is  too  low.  At  the  end  of  each  arm  has  been  left  a  fruit  cane 
and  a  renewal  spur.  As  the  vine  is  exceptionally  vigorous  an  extra 
fruit  cane  has  been  left  near  the  middle  of  an  arm  to  the  right.  The 
lower  cane  to  the  left  is  too  long  for  so  weak  a  cane.  The  other  canes 
are  very  vigorous  and  the  number  of  fruit  buds  has  been  increased  by 
leaving  1  or  2  joints  of  the  strong  "laterals"  on  these  canes. 


Circular  245] 


VINE   PRUNING   SYSTEMS 


Fig.  3. — Cordon  pruned  Emperor  four  years  old. 


3.  Cordon  pruning. — In  this  system  the  vine  is  given  a  long,  rela- 
tively slender  trunk  which  extends  horizontally  at  about  30  inches 
from  the  ground  until  it  reaches  the  next  vine.  On  top  of  this  trunk 
along  its  horizontal  part  are  developed  upright  arms,  4  to  12  inches 
long  at  intervals  of  8  to  12  inches.  The  annual  growth  left  at  the 
winter  pruning  consists  of  spurs  or  rarely  of  fruit  canes  at  the  end 
of  these  arms. 

Figure  3  shows  a  cordon-pruned  vine  of  good  form.  It  consists  of 
a  trunk  about  10  feet  long  which  rises  from  the  ground  in  a  smooth 
curve  or  quarter  circle  and  then  extends  horizontally  along  a  wire  at 
30  inches  from  the  ground  until  it  reaches  the  next  vine. 

On  this  trunk,  commencing  at  the  point  where  it  becomes  hori- 
zontal have  been  left  spurs  of  2  to  3  joints  about  every  12  inches.  As 
the  vine  becomes  older  these  spurs  will  gradually  develop  into  arms, 
on  the  end  of  each  of  which  will  be  left  1  or  2  similar  spurs.  The 
height  of  these  spurs  from  the  ground,  and  consequently  the  position 
of  the  fruit,  can  be  modified  by  developing  arms  of  greater  or  less 
length. 

ADVANTAGES    OF    EACH    SYSTEM 

Where  head  pruning  is  adopted,  the  vines  require  no  trellises  and 
may  therefore  be  planted  so  that  cross  cultivation  is  possible.  Stakes 
are  necessary  at  first,  but  they  can  usually  be  discarded  after  4  to  6 
years  when  the  trunks  of  the  vines  have  developed  sufficiently  to  be 
self-supporting.  This  is  the  easiest  system  to  establish,  but  consider- 
able care  and  skill  are  required  to  keep  the  vines  in  shape  as  they  grow 
older. 

Cane  pruning  is  necessary  for  varieties  which  will  not  bear  well 
on  short  spurs.    It  requires  a  permanent  horizontal  trellis  consisting 


4  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

of  a  well-supported  horizontal  No.  12  galvanized  iron  wire  at  about 
30  to  40  inches  from  the  ground  to  which  the  fruit-canes  are  attached 
in  order  to  increase  their  fruitfulness  and  to  prevent  them  from  shad- 
ing the  renewal  spurs  which  need  sunlight  to  produce  good  fruit  canes 
for  the  following  year.  A  similar  wire  is  usually  placed  about  12 
inches  above  the  first  to  support  the  growing  shoots.  This  system  is 
fairly  simple  to  establish  but  vines  pruned  by  it  are  the  most  difficult 
to  keep  in  shape  when  they  become  large. 

Cordon  pruning  is  necessary  for  varieties  which  do  not  bear  suf- 
ficiently on  spurs  and  which  produce  grapes  of  inferior  quality  on 
canes.  It  is  useful  also  for  most  vigorous,  large-fruited  varieties  of 
table  grapes.  It  requires  a  permanent  trellis  similar  to  that  used  in 
cane  pruning  to  support  the  horizontal  trunk.  Some  of  its  advantages 
are  that  it  increases  the  fruitfulness  of  the  canes  so  that  nearly  all 
varieties  will  bear  on  the  lowest  buds,  and  that  it  promotes  large  size 
of  the  berries  and  bunches,  and  high  uniform  quality.  It  is  the  most 
laborious  of  the  three  to  establish  during  the  first  four  years,  but, 
when  established,  it  is  the  simplest  and  perhaps  the  most  economical 
to  maintain. 

CHOICE   OF  A  SYSTEM 

In  nearly  all  cases  where  the  head  pruning  system  is  known  to  give 
perfectly  satisfactory  results,  it  should  be  chosen.  It  is  the  most 
economical  and  best  understood  by  most  grape  growers.  It  usually 
gives  good  results  with  the  following  varieties  of  grapes : 

Medium  trunk:  Muscat,  Verdal,  Palomino,  Zinfandel,  Alicante 

Bouschet,  Duriff  (Petite  Sirah),  Beclan,  Grand  Noir. 
High  trunk:    Tokay,   Rose   of   Peru,   Black   Prince,   Mission, 
Malaga. 

Cane  pruning  should  be  adopted  only  when  neither  of  the  other 
systems  gives  as  good  results.  It  is  used  almost  always  for  Sultanina, 
Sultana,  Black  Corinth,  Pierce,  Concord,  Isabella,  Catawba,  and  most 
Labrusca  varieties. 

Cordon  pruning  can  be  recommended  for  Emperor,  Ohanez,  Corni- 
chon,  Molinera,  Black  Monukka,  Zabalkanski,  and  most  vigorous  large- 
fruited  table  grapes,  especially  when  growing  in  very  fertile  soil. 

For  general  information  regarding  vine  pruning,  see  Bulletin  241- 
246,  ' '  Vine  Pruning  in  California. ' '  For  special  directions  regarding 
these  three  systems,  see,  for:  Head-pruning,  Bulletin  241-46,  pp.  69- 
88;  Cane-pruning,  Circular  191,  "Pruning  the  Seedless  Grapes"; 
Cordon-pruning,  Circular  229,  "Cordon  Pruning." 


